What is Testosterone, Total (Dried Blood Spot)?
Testosterone is the principal androgen in males, synthesised predominantly by Leydig cells under luteinising-hormone control, with smaller contributions from the adrenal cortex. It circulates largely bound to sex hormone-binding globulin and albumin, with a free fraction of one to two per cent. Dried-blood-spot collection captures total testosterone concentration from capillary blood, which correlates well with venous serum when measured by LCMS but requires method-specific reference intervals.